1. Field of the Invention
The present invention generally relates to a lane departure prevention apparatus for preventing a host vehicle from departing from a driving lane when the host vehicle is about to depart from the lane or departure seems imminent.
2. Background Information
Conventional lane departure prevention apparatuses include apparatuses for imparting yaw moment to the host vehicle by controlling the braking force to the wheel and preventing the host vehicle from deviating from the driving lane. These conventional lane departure prevention apparatuses also inform the driver that the host vehicle may possibly depart from the driving lane by providing this yaw moment in cases in which there is a possibility that the host vehicle may depart from a driving lane. For example, one such lane departure prevention apparatus is disclosed in Japanese Laid-Open Patent Publication No. 2000-33860, which controls the brakes to provide a yaw moment to the host vehicle and prevents lane departure, and which also warns the driver through this yaw moment (see, page 3 and FIG. 6). This conventional lane departure prevention apparatus determines a lane departure by whether or not any of the distance from a driving lane center of a host vehicle driving position (lateral shift amount) and the angle that an estimated driving course forms with respect to the driving lane (yaw angle shift amount) has exceeded respective predetermined values.
Another lane departure prevention apparatus is disclosed in Japanese Laid-Open Patent Publication No. 2003-112540 (p. 7 and FIG. 2), which evaluates the lane departure of the host vehicle from its driving lane, and avoids lane departure by combining yaw control and deceleration control. In particular, the yaw control applies the brakes to provide a yaw moment to the host vehicle in which a braking force difference is applied to the left and right wheels to avoid lane departure, while the deceleration control applies the brakes to decelerate the host vehicle. The total braking force of the yaw control and the deceleration control is applied according to the amount by which the vehicle is estimated to depart from its lane in the future, which is calculated on the basis of the driving state of the host vehicle.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved lane departure prevention apparatus. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.